Signals get shaken and stirred

A medical emergency can happen any time, especially if you’re James Bond. That’s just the reality when you spend your life falling out of planes, getting into car chases, and having lasers aimed at your netherparts. In Casino Royale, though, the inventive people in Q Division come up with a way to monitor 007’s health remotely, using a radio device. Before too long, it comes in handy. During a high stakes poker game Bond’s martini is poisoned, and under the watchful, bloody eye of the villain, Le Chiffre, Bond staggers out of the casino. Everyone back at MI6 knows Bond’s in trouble thanks to the health monitor, and they’re able to help him give himself the antidote to the poison. As the scene ends he’s being accompanied back to the casino by a beautiful companion, and almost certainly not thinking how lucky he was that his radio monitor had good reception.

Which might be just as well. If Bond knew how tricky it is to get radio waves to work around the human body, it would have only added to his worries. Fortunately, though, electrical engineers are on the case – real ones too, not just the ones who work in James Bond’s film universe. Real ones like Akram Alomainy and Yang Hao at Queen Mary, University of London, who are part of a project to develop wearable antennas so that doctors can monitor patients remotely.

Feeling electric

Here’s the problem: it’s really difficult to communicate around the human body. It sounds weird, but our bodies have electric properties that can change how radio waves behave around them. For example, a body can alter the frequency of a radio wave, or block it altogether. What’s more, since bodies change position all the time, a radio wave is never going to be changed in a consistent way. It all adds up to a headache for engineers like Akram and Yang designing a wireless network to be attached to the body.

That’s a shame, because as James Bond’s medical monitor shows, remote sensing can be pretty handy. It’s likely to be more and more useful in the coming years, as the population gets older and needs more medical care. A good solution could be to monitor people with heath problems as they go about their lives. Just like in Casino Royale, doctors would be alerted in case anyone took a turn for the worse – whether they had an asthma attack, or perhaps less likely, were poisoned by a megalomaniac.

Please repeat that

Let’s say you’re wearing a few sensors that monitor your health, all networked together to send reports back to a base. Making that network communicate over various parts of your body is difficult. Akram and Yang’s team are trying to help get around the problem of your own pesky, radio-blocking body by finding ways to boost the signal at various points around the body with ‘repeaters’. Repeaters receive a weak signal from the monitor and add a bit of power to it before sending it on its way. The team use real-world experiments and mathematical simulations to try and figure out the best places to put the repeaters so that the whole network’s signal works consistently. For example, it turns out that radio signals can become trapped between layers of the body, like between skin and fat. The signal will then find the easiest route to escape the body, which is often out the back. So you might want to put a repeater on a person’s back to catch those signals and relay them.

You might be wondering why you don’t normally hear about your body interfering with radio signals even though we use mobile phones all the time. The reason your mobile is able to get around the problem of your body interfering is because manufacturers just turn the power of the signal way up. This uses up the batteries quicker, but since people can always plug their phones in at the end of the day, battery life isn’t such a problem. In the case of medical devices, though, you wouldn’t want someone to have to take off their monitors every day to recharge them – it would defeat the whole purpose.

Let’s get physical

Medical devices aren’t the only reason to put computer networks on your body. You might want a system for when you’re jogging that chooses music with a beat that matches your heart rate. Or you might want your house to know how warm you are, so it can turn up the heat automatically when you’re feeling chilly. Maybe you’d hook a bunch of personal networks together, so that everyone at a club would control the lights with their level of excitement.

Human bodies are pretty weird in lots of ways, including being able to mess around with radio waves. So it’s kind of comforting to know that when those bodies go wrong, engineers like Akram have already thought about how to make sure doctors will find out about it. Leaving us to get back to any high-stakes poker games we might have left in a hurry.